Merge pull request #2329 from jason-simmons/suspend_skia_crash

Clear the Flow raster cache when a GrContext is destroyed

engine/src/flutter/flow/paint_context.cc

@@ -49,4 +49,8 @@ PaintContext::ScopedFrame::~ScopedFrame() {
 PaintContext::~PaintContext() {
 }
 
+void PaintContext::OnGrContextDestroyed() {
+  raster_cache_.Clear();
+}
+
 }  // namespace flow

engine/src/flutter/flow/paint_context.h

@@ -51,6 +51,8 @@ class PaintContext {
                            SkCanvas& canvas,
                            bool instrumentation_enabled = true);
 
+  void OnGrContextDestroyed();
+
   RasterCache& raster_cache() { return raster_cache_; }
   const instrumentation::Counter& frame_count() const { return frame_count_; }
   const instrumentation::Stopwatch& frame_time() const { return frame_time_; }

engine/src/flutter/flow/raster_cache.cc

@@ -112,4 +112,8 @@ void RasterCache::SweepAfterFrame() {
     cache_.erase(it);
 }
 
+void RasterCache::Clear() {
+  cache_.clear();
+}
+
 }  // namespace flow

engine/src/flutter/flow/raster_cache.h

@@ -25,6 +25,8 @@ class RasterCache {
       GrContext* context, SkPicture* picture, const SkMatrix& ctm);
   void SweepAfterFrame();
 
+  void Clear();
+
  private:
   struct Entry {
     Entry();